Systems and methods for terminating telephony communications to mobile telephony devices

ABSTRACT

Systems and methods for terminating telephony communications to a mobile telephony device that is roaming outside of its native service area make use of a forwarding termination service. The forwarding termination service causes the native mobile telephony service provider that provides service to the mobile telephony device to forward incoming telephony communications directed the native telephone number of the mobile telephony device to a forwarding access number. The forwarding termination service receives telephony communications directed to the forwarding access number, and then terminates the telephony communication to the mobile telephony device via any one of multiple different methods. The mobile telephony service provider can be instructed to implement and cancel call forwarding instructions by dialing a special character string on the mobile telephony device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 13/492,361, filed Jun. 8, 2012, which is itself acontinuation-in-part of U.S. patent application Ser. No. 13/334,849,filed Dec. 22, 2011, the entire contents of both of which are hereinincorporated by reference.

FIELD OF THE INVENTION

The invention is related to systems and methods for terminatingtelephony communications to a telephony device. More specifically, theinvention relates to systems and methods for terminating telephonycommunications to a telephony device via a non-native Voice overInternet Protocol telephony system.

BACKGROUND OF THE INVENTION

Mobile telephony devices, such as cellular telephones and mobilecomputing devices with cellular telephony capabilities, are typicallyprovided with service from a cellular service provider. The cellularservice provider typically only provides service to its customers withina defined geographical area, often only within a single country. Thearea served by the provider is considered the “native” service area forcustomers who receive cellular telephone service from the provider.

If a customer who receives cellular telephone service from a first“native” cellular service provider travels to an area outside his nativeservice area, the customer's cellular telephone may be capable ofreceiving cellular service from a second “non-native” cellular serviceprovider that provides coverage in that location. However, because thenon-native cellular service provider is not the customer's regularservice provider, the customer will be charged special “roaming” feesfor receiving incoming communications and for sending outgoingcommunications from that location. Typically, the non-native cellularservice provider charges the user's native cellular service provider forproviding service to the customer's cellular telephone, and the nativecellular service provider then passes those charges along to thecustomer as part of his regular monthly bill. This is true for telephonecalls, text messages, and other forms of telephony communications.

Roaming charges can be exorbitant compared to fees charged for telephonycommunications within the customer's native service area. Internationalroaming charges are particularly expensive, as the rates negotiatedbetween carriers for overseas call termination has been at a premium.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a system level representation of elements that interact witheach other to terminate telephony communications to mobile telephonydevices;

FIG. 2 is a schematic diagram of a controller that may be used topractice one or more embodiments of the present invention;

FIG. 3 is a block diagram illustrating elements of a forwardingconnection unit embodying the invention;

FIG. 4 is a diagram illustrating steps of a method embodying theinvention for registering a mobile telephony device with a forwardingtermination service;

FIG. 5 is a diagram illustrating steps of a method embodying theinventor for implementing call forwarding instructions as part of amethod of terminating telephony communications to mobile telephonydevices;

FIG. 6 is a diagram illustrating steps of a method embodying theinventor for triggering the implementation of call forwardinginstructions as part of a method of terminating telephony communicationsto mobile telephony devices;

FIG. 7 is a diagram illustrating steps of a method embodying theinventor for terminating telephony communications to a mobile telephonydevice;

FIG. 8 is a diagram illustrating steps of another method embodying theinvention for terminating telephony communications to a mobile telephonydevice;

FIG. 9 is a flowchart describing a method in which a character stringthat can be dialed to implement call forwarding is determined andprovided to a telephony device;

FIG. 10 is a flowchart describing another method in which in which acharacter string that can be dialed to implement call forwarding isdetermined and provided to a telephony device; and

FIG. 11 is a flowchart describing a method in which a mobile telephonydevice is caused to dial a character string that causes theimplementation of call forwarding instructions.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the following description, references are made to a user's or acustomer's telephony device. This term encompass traditional cellulartelephones, as well as mobile telephony devices that include additionalfunctionality, such as the ability to wirelessly communicate digitaldata. These terms also encompass mobile computing devices that includecommunications capabilities provided by either or both of a cellulartransceiver and a wireless digital data transceiver. Examples of suchdevices include the Apple iPhone™, the Apple iPod Touch™, mobiletelephony devices running the Android™ operating system, the Blackberry™and mobile telephones running the Symbian operating system.

The following description also refers to terminating a telephonycommunication. This phrase refers to completing an incoming telephonycommunication, such as a voice or video telephone call, to a telephonydevice. This phrase also encompasses delivering text messages and otherforms of text-based or video-based messaging to a telephony device. Thisphrase also encompasses other forms of communications that may becarried over a telephony network.

The term “call” or “telephone call” is used in the following descriptionfor ease of reference, clarity and brevity. However, all of the systemsand methods described below which involve handling, routing andterminating calls would also apply to systems and methods of handling,routing and terminating other forms of telephony-based communications.Thus, the terms call and telephone call are intended to include otherforms of telephony-based communications.

The invention provides a method, system and apparatus for terminating atelephony communication to a telephony device via a Voice over InternetProtocol (VOIP) telephony system. In some instances, the telephonycommunication is terminated to the telephony device through the VOIPtelephony system because the telephony device is roaming, and roamingcharges would otherwise be applied if the telephony communication wasterminated in a traditional fashion. Terminating the telephonycommunication through the VOIP telephony system makes it possible toavoid the roaming charges. In other instances, the telephonycommunication is terminated through the VOIP telephony system for someother reason, as will be explained below.

In some instances, however, such as where no other options exist, the IPtelephony system might deliberately cause the telephony communication tobe terminated to a roaming telephony device in a traditional fashionthrough a non-native mobile telephony service provider. While this wouldresult in the user incurring roaming charges, terminating the telephonycommunication in this fashion may be the only way to reach the user.

In some systems and methods embodying the invention, telephonycommunications are effected over a packet-based data network. Signalingthat is conducted in the packet-based data network is preferablyexecuted using Session Initiation Protocol (SIP). SIP is a popularcommunication protocol for initiating, managing and terminating media(e.g., voice, data and video) sessions across packet-based data networksthat typically use the Internet Protocol (IP), of which Voice OverInternet Protocol (VOIP) is an example. The details and functionality ofSIP can be found in the Internet Engineering Task Force (IETF) Requestfor Comments (RFC) Paper No. 3261 entitled, “SIP: Session InitiationProtocol” herein incorporated in its entirety by reference.

SIP establishes and negotiates a session, including the modification ortermination of a session. It uses a location-independent address systemfeature in which called parties can be reached based on a party's name.SIP supports name mapping and redirection, allowing users to initiateand receive communications from any location. Of course, while SIP is apreferred protocol for establishing communications over a data network,other signaling protocols could also be used to perform the invention.

The following description provides examples of how the invention can beused to terminate telephony communications to a mobile telephone devicevia a VOIP telephony system. The mobile telephony device could be acellular telephone or a smart phone. However, the invention is alsoapplicable to other types of telephony devices. Thus, the reference to amobile telephony device should not be considered in any way limiting.Systems and methods embodying the invention can also be used toterminate telephony communications to telephony devices other thantraditional mobile telephony devices.

FIG. 1 depicts various elements that may be involved in terminatingtelephony communications to a mobile telephony device. The elements inFIG. 1 include a subscriber mobile telephony device 112. The subscribermobile telephony device 112 may have a native ability to handle voiceover Internet protocol telephony communications sent via a data channel.In other instances, an application running on the subscriber mobiletelephony device 112 may provide the capability of handling voice overInternet protocol telephony communications sent via a data channel. Instill other instances, as explained more fully below, a browser on asubscriber mobile telephony device 112 may access a software applicationthat is running on a processor located elsewhere, and the softwareapplication may provide the capability of handling voice over Internetprotocol telephony communications sent via a data channel.

Mobile telephony service provider A 114 is located in country 1 andprovides telephony service to mobile telephony devices located incountry 1. Mobile telephony service provider A 114 could be, forexample, a cellular telephone network. For purposes of the followingdescription, mobile telephony service provider A 114 is the nativemobile telephony service provider that provides service to thesubscriber mobile telephony device 112.

FIG. 1 also depicts a traditional publically switched telephone network(PSTN) 130. An analog telephone 132 can utilize the PSTN 130 to placeand receive calls. The analog telephone 132 could call the subscribermobile telephony device 112, and the call would be routed through thePSTN 130, then through mobile telephony service provider B 140 to thesubscriber mobile telephony device 112.

FIG. 1 also depicts a cellular telephone 110 that is provided withservice by mobile telephony service provider A 114. The cellulartelephone 110 could call the subscriber mobile telephony device 112through mobile telephony service provider B 140.

FIG. 1 further depicts an IP telephony device 111 that maintains a dataconnection to a packet network, such as the Internet 116. The IPtelephony device 111 is provided with telephony service by an IPtelephony system 124 which is also connected to the Internet 116. If theuser of the IP telephony device 111 wishes to establish a call with thesubscriber mobile telephony device 112, the IP telephony device 111sends a call setup request to the IP telephony system 124 via theInternet 116. The IP telephony system 124 then routes the call throughmobile telephony service provider B 140 to the subscriber mobiletelephony device 112. FIG. 1 also depicts that the IP telephony system124 may use gateways 120A, 120B to communicate with the PSTN 130, mobiletelephony service provider A 114, as well as other telephony serviceproviders.

FIG. 1 further depicts that mobile telephony service provider B 140 islocated in country 2 and provides service to mobile telephony deviceslocated in country 2. Mobile telephony service provider B 140 could alsobe a cellular service provider.

Finally, FIG. 1 illustrates that the subscriber mobile telephony device112 is located in country 2, and it is capable of wirelessly accessingthe Internet 116 via a wireless interface 118. This allows thesubscriber mobile telephony device 112 to send and receive datacommunications over the Internet 116. The wireless interface 118 couldbe a wireless router operating under the WiFi or WiMax standards, or anyother type of wireless interface device that is capable of communicatingwith the subscriber mobile telephony device 112 and the Internet 116. Inother instances, the subscriber mobile telephony device 112 couldestablish a data link to the Internet, or to some other data network, inother ways. For example, the subscriber mobile telephony device 112could communicate through a wireless Local Area Network (LAN), a WideArea Network (WAN) gateway, a hardwired Internet connection and thelike.

Although the subscriber mobile telephony device 112 is capable ofsending and receiving data communications through the wireless interface118, the subscriber mobile telephony device 112 is also capable ofestablishing a data channel through a mobile telephony service provider.The data channel would be separate from a channel used for audiocommunications. Thus, the subscriber mobile telephony device 112 iscapable of sending and receiving data communications via two independentpathways.

As explained above, mobile telephony service provider A 114, located incountry 1, is the native service provider for the subscriber mobiletelephony device 112. When located in country 2, the subscriber mobiletelephony device 112 only has access to mobile telephony serviceprovider B 140 to send and receive telephony communications. Thisresults in the subscriber incurring roaming charges.

As will be described in more detail below, elements of the IP telephonysystem 124 are capable of terminating telephony communications to thesubscriber mobile telephony device 112 via a data connection passingover the Internet 116. In some instances, the IP telephony system 124may also be capable of terminating telephony communications to thesubscriber mobile telephony device 112 via a data connection passingover a data channel provided by mobile telephony service provider B 140.So long as the cost of obtaining that data connection is lower than thecost of receiving a telephone call via mobile telephony service providerB 140 over a mobile voice channel, this may be a preferred way ofterminating the telephony communication to the subscriber mobiletelephony device 112.

FIG. 2 illustrates elements of a computer processor 250 that can be usedas part of the system operated by the IP telephony service provider 124to accomplish various functions. The IP telephony service provider 124could utilize multiple processors 250 located at various locations,along with their operating components and programming, each carrying outa specific or dedicated portion of the functions performed by the IPtelephony service provider 124.

The processor 250 shown in FIG. 2 may be one of any form of a generalpurpose computer processor used in operating an IP based communicationsystem. The processor 250 comprises a central processing unit (CPU) 252,a memory 254, and support circuits 256 for the CPU 252. The processor250 also includes provisions 258/260 for connecting the processor 250 tocustomer equipment via one or more access point, such as the packetnetwork 116, gateways 120A, 120B and a data channel provided by acellular service provider, as well as possibly one or more input/outputdevices (not shown) for accessing the processor and/or performingancillary or administrative functions related thereto. The provisions258/260 are shown as separate bus structures in FIG. 2; however, theymay alternately be a single bus structure without degrading or otherwisechanging the intended operability of the processor 250.

Another form of processor 250 that assists in execution and is otherwisepart of the subject invention is found within one or more of the mobiletelephony devices. Such devices are sufficiently advanced beyond earlygeneration cellular telephones that they contain processors capable ofrunning operating systems developed by device manufactures, as well asthird party applications that are downloaded and installed by users toperforming a myriad of communications and non-communications orientedtasks.

The memory 254 is coupled to the CPU 252. The memory 254, orcomputer-readable medium, may be one or more of readily available memorysuch as random access memory (RAM), read only memory (ROM), floppy disk,hard disk, flash memory or any other form of digital storage, local orremote, and is preferably of non-volatile nature. The support circuits256 are coupled to the CPU 252 for supporting the processor in aconventional manner. These circuits include cache, power supplies, clockcircuits, input/output circuitry and subsystems, and the like.

A software routine 262, when executed by the CPU 252, causes theprocessor 250 to perform processes of the disclosed embodiments, and isgenerally stored in the memory 254. The software routine 262 may also bestored and/or executed by a second CPU (not shown) that is remotelylocated from the hardware being controlled by the CPU 252. Also, thesoftware routines could also be stored remotely from the CPU. Forexample, the software could be resident on servers and memory devicesthat are located remotely from the CPU, but which are accessible to theCPU via a data network connection.

The software routine 262, when executed by the CPU 252, transforms thegeneral purpose computer into a specific purpose computer that performsone or more functions of the IP telephony system 124. Although theprocesses of the disclosed embodiments may be discussed as beingimplemented as a software routine, some of the method steps that aredisclosed therein may be performed in hardware as well as by a processorrunning software. As such, the embodiments may be implemented insoftware as executed upon a computer system, in hardware as anapplication specific integrated circuit or other type of hardwareimplementation, or a combination of software and hardware. The softwareroutine 262 of the disclosed embodiments is capable of being executed onany computer operating system, and is capable of being performed usingany CPU architecture.

The IP telephony system 124 includes a forwarding connection unit 300,as illustrated in FIG. 3. The forwarding connection unit 300 includes aregistration unit 302, a triggering unit 304, a forwarding instructionunit 306, a call termination unit 308, and an optional call forwardingcode database 310. These elements act together to register a mobiletelephony device with a forwarding termination service provided by theIP telephony system 124. These elements also act to determine when theforwarding termination service should be activated or deactivated, andto route telephony communications to registered telephony devices whenthe forwarding termination service is activated. Whenever possible, theforwarding connection unit 300 terminates telephony communications to atelephony device in a manner that does not result in the user incurringroaming charges.

In some embodiments, any time that the subscriber mobile telephonydevice 112 detects the availability of a data network connection, suchas through the wireless interface 118, the subscriber mobile telephonydevice 112 contacts the forwarding connection unit 300 and registerswith same. Once registered, the IP telephony system 124 is capable ofrouting telephony communications to the subscriber mobile telephonydevice 112 via the data network connection. In some embodiments,however, the subscriber mobile telephony device 112 may only attempt toregister with the forwarding connection unit 300 if the subscribermobile telephony device determines that it is outside of its nativeservice area and is roaming. In still other embodiments, the subscribermobile telephony device 112 may attempt to register with the forwardingconnection unit 300 when it is still within its native service area, butwhen the device is unable to establish a connection to its native mobiletelephony service provider.

In other instances, a subscriber mobile telephony device 112 may attemptto register with the forwarding connection unit 300 for other reasons.For example, any time that the cost to receive a telephony communicationvia a native or non-native mobile telephony service provider exceeds athreshold value, the subscriber mobile telephony device 112 may beconfigured to instead register with the forwarding connection unit 300of an IP telephony system to avoid those charges. This could occur evenif the subscriber mobile telephony device 112 never leaves its nativeservice area.

In some instances, the subscriber mobile telephony device 112 maydeliberately choose to register itself with the forwarding connectionunit 300 when it is within its native service area, and when a cellularchannel to mobile telephony service provider A 114 is available. Thismight allow the subscriber mobile telephony device 112 to receiveincoming calls without using up minutes of a calling plan. In thisinstance, the subscriber might configure his subscriber mobile telephonydevice 112 such that whenever the subscriber device 112 detects theavailability of a data network connection, such as a wireless router 118connected to the Internet 116, use of the system and methods describedabove are automatically initiated.

The registration unit 302 acts to register individual mobile telephonydevices with the forwarding termination service. Typically a subscriberwill already have an existing account with the IP telephony system 124.However, in some instances, a subscriber could register for theforwarding termination service only for purposes of obtaining theforwarding termination service from the IP telephony system 124.

FIG. 4 illustrates steps of a method of registering a mobile telephonydevice with the forwarding termination service. As illustrated in FIG.4, in step S402, the registration unit 302 obtains the native telephonenumber associated with the subscriber mobile telephony device 112. Thisnative telephone number may have been assigned by mobile telephonyservice provider A 114, or by some other mobile telephony serviceprovider. The registration unit 300 then creates a new entry in aregistration database for the subscriber mobile telephony device 112that includes the native telephone number.

In step S404, the registration unit 302 obtains an identifier associatedwith the subscriber mobile telephony device 112 from mobile telephonyservice provider A 114. In one embodiment of the invention, theidentifier is an international mobile subscriber identity (IMSI) number.The IMSI number is a unique identifier associated with all GSM and UMTSnetwork mobile telephone users and conforms to the ITU E.212 numberingstandard.

The IMSI number is actually associated with the SIM card present in thesubscriber mobile telephony device 112, and it would be contained in ahome location register that is maintained by mobile telephony serviceprovider A 114. The IMSI number is often required to be used in certaincommunications with a mobile telephony service provider when the mobileservice provider is being asked to take certain actions with respect toa mobile telephony device. In step S406, the registration unit 302stores the IMSI number in the record established for the subscribermobile telephony device 112 in the registration database.

Once the subscriber mobile telephony device 112 has been registered, theforwarding connection unit 300 will have the information it requires tocause telephony communications directed to the regular native telephonenumber associated with the subscriber mobile telephony device 112 to bere-directed to the IP telephony system 124. This is accomplished byinstructing mobile telephony service provider A 114 to forward callsdirected to the native telephone number associated with the subscribermobile telephony device 112 to a forwarding access number that ismaintained by the IP telephony system 124. Once call forwardinginstructions have been implemented, all calls placed to the nativetelephone number of the subscriber mobile telephony device 112 will bereceived by the IP telephony system 124 via the forwarding accessnumber. In some embodiments, this would be accomplished using the RTPand SIP protocols. The IP telephony system 124 can then terminate thecall to the subscriber mobile telephony device 112 in a fashion thatwill not incur roaming charges.

The above description refers to obtaining a native telephone numberassociated with the subscriber mobile telephony device 112. In alternateembodiments, instead of obtaining a native telephony number, one mightobtain some other form of identifier that is associated with thesubscriber mobile telephony device 112, and which is used to facilitatethe termination of telephony communications to the subscriber mobiletelephony device 112. The other identifiers may include a user name, analias, a proxy, and identification number, or any other sort of uniqueidentifier which can be used to help route telephony communications tothe subscriber mobile telephony device 112. Although the examples givenabove and below refer to a telephone number, or a native telephonenumber, these terms are intended to encompass other forms of uniqueidentifiers. Systems and methods embodying the invention will workequally well with telephone numbers and other forms of identifiers.

Likewise, the above description refers to a forwarding access telephonenumber. In alternate embodiments, instead of assigning a forwardingaccess telephone number, some other type of forwarding identifier may beassigned. The forwarding identifier could be a user name, an alias, aproxy, and identification number, or any other sort of unique identifierwhich can be used to help route telephony communications to the IPtelephony system 124. In those instances, the native mobile serviceprovider will be instructed to forward any incoming telephonycommunications that that are directed to the native telephone number ofa subscriber mobile telephony device 112 to the assigned forwardingidentifier. In the foregoing and following description, the term “accesstelephone number” and “forwarding access telephone number” are used.However, these terms are intended to encompass other forms of forwardingidentifiers other than telephone numbers.

FIG. 5 illustrates steps of a method that would be performed by theforwarding connection unit 300 to cause the implementation of callforwarding instructions. The method starts in step S502 when thetriggering unit 304 of the forwarding connection unit 300 decides thatforwarding instructions should be issued. The triggering unit 304determines that it is appropriate to implement call forwardinginstructions in response to a variety of different conditions, as willbe described in more detail below.

In step S504, the forwarding instruction unit 306 assigns a forwardingaccess telephone number. The forwarding access telephone number (orother forwarding identifier) is stored in a registration databasemaintained by the IP telephony system 124 against the native telephonenumber (or other type of identifier) of the subscriber mobile telephonydevice 112. The forwarding access telephone number may also be storedagainst an IMSI number associated with the subscriber mobile telephonydevice 112, and/or a SIM card that is present in the subscriber mobiletelephony device 112. Once the forwarding access number has beenassigned, in step S506 the forwarding instruction unit 306 issues callforwarding instructions to mobile telephony service provider A 114 tocause mobile telephony service provider A 114 to forward all calls madeto the native telephone number of the subscriber mobile telephony device112 to the assigned forwarding access number.

In some instances, the IMSI number for a subscriber mobile telephonydevice 112 may be used in the communications with the mobile telephonyservice provider A 114 to cause the implementation of the callforwarding instructions. In other embodiments, the IMSI number may notbe required. In still other embodiments, some other type ofidentification number associated with the subscriber mobile telephonydevice 112 may be used in such communications.

The forwarding access telephone number (or other forwarding identifier)is controlled by the IP telephony system 124. Once the call forwardinginstructions have been implemented, any calls made to the nativetelephone number of the subscriber mobile telephony device 112 arereceived by the IP telephony system 124. Also, when the IP telephonysystem 124 receives a call directed to a forwarding access telephonenumber, the IP telephony system 124 consults the registration databaseto determine which subscriber mobile telephony device 112 is associatedwith that forwarding access telephone number. In this fashion, the IPtelephony system 124 knows which mobile telephony device the caller istrying to reach.

The subscriber mobile telephony device 112 registers itself with theforwarding connection unit 300 via communications that pass over a datanetwork. Those communications could be sent to the forwarding connectionunit 300 over the Internet, via a wireless interface 118. Thosecommunications could also pass over a data channel of a cellularconnection. Regardless, the subscriber mobile telephony device 112contacts the forwarding connection unit 300 and provides information,such as an IP address and a port number, that allows the forwardingconnection unit 300 to contact the subscriber mobile telephony device112 and establish a voice over Internet protocol link with thesubscriber mobile telephony device 112. This information would also bestored in the registration database against the other information beingmaintained for the subscriber mobile telephony device 112.

Once call forwarding instructions have been issued, and once thesubscriber mobile telephony device 112 has registered with theforwarding connection unit 300, the forwarding connection unit 300 canroute incoming calls to the subscriber mobile telephony device 112through a data network. The forwarding connection unit 300 establishes aVOIP call with the subscriber mobile telephony device 112, and that callis then connected to the inbound call forwarded from mobile telephonyservice provider A 114.

Because the incoming call is routed through the data network, ratherthan through non-native mobile telephony service provider B 140, noroaming charges will be incurred by the user. The user may have to payto obtain access to the data network. But in many instances, the cost ofaccessing the data network will be lower than the cost of roamingcharges that would otherwise be incurred. For example, if the subscribermobile telephony device 112 uses a wireless access point, such as a WiFirouter, to obtain access to the data network, the charges for suchaccess would likely be far lower than the cost of roaming charges. Evenwhen the subscriber mobile telephony device 112 uses a cellular datachannel to obtain access to a data network, the user would likely incurlower charges for data access than the cost of typical roaming charges.

When the subscriber mobile telephony device 112 registers with theforwarding connection unit 300, this event may trigger the forwardinginstruction unit 306 to issue call forwarding instructions to mobiletelephony service provider A 114. However, a variety of other triggeringevents might also cause the forwarding instruction unit 306 to issuecall forwarding instructions. Also, the triggering events that cause theimplementation or cancellation of call forwarding instructions could becustomized for an individual user or for an individual subscriber mobiletelephony device.

In order for a telephony communication to be terminated to thesubscriber mobile telephony device 112 via the forwarding connectionunit, two actions must occur. First, a connection must be establishedbetween the forwarding connection unit and the subscriber mobiletelephony device 112 via a data network link. Second, the nativetelephony service provider for the subscriber mobile telephony device112 must be instructed to forward incoming telephony communicationsdirected to the native telephone number of the subscriber mobiletelephony device 112 to a forwarding access telephone number controlledby the IP telephony system 124. In some instances, the forwarding accesstelephone number may have already been assigned to the subscriber mobiletelephony device 112. In other instances, it will be necessary to assignthe forwarding access number before the native mobile telephony serviceprovider can be instructed to cause call forwarding to occur. Once theseactions have occurred, it is possible for an incoming telephonycommunication directed to the native telephone number of the subscribermobile telephony 112 device to be terminated to the subscriber mobiletelephony device 112 via the forwarding connection unit. Collectively,the actions outlined above which must be taken to allow an incomingtelephony communication directed to the native telephone number of thesubscriber mobile telephony 112 device to terminated to the subscribermobile telephony device 112 via the forwarding connection unit arereferred to as implementing forwarding termination procedures.

Conversely, canceling forwarding termination procedures refers toactions that must occur to resume normal termination of telephonycommunications to the subscriber mobile telephony device 112. In mostinstances, this only requires providing instructions to the nativemobile telephony service provider that cause previously implemented callforwarding instructions to be canceled.

In some embodiments, the triggering unit 304 of the forwardingconnection unit 300 will monitor or periodically check one or more itemsof information to determine whether forwarding termination proceduresshould be implemented. If so, the triggering unit may cause theforwarding termination procedures to be automatically implemented. Inother embodiments, the triggering unit may send a query to the user ofthe subscriber mobile telephony device 112 to ask whether the userwishes to have forwarding termination procedures implemented. Only ifthe user responds affirmatively will the triggering unit 304 cause theforwarding procedures to be implemented.

In a similar manner, once forwarding termination procedures have beenimplemented, the triggering unit 304 may monitor or periodically checkone or more items of information to determine if forwarding terminationprocedures should be canceled. If so, the triggering unit mayautomatically cancel the forwarding termination procedures, or thetriggering unit may obtain user approval for cancelation of theforwarding termination procedures before acting.

In still other embodiments, an application that is running on a user'stelephony device may monitor or periodically check one or more items ofinformation to determine whether forwarding termination proceduresshould be implemented and/or canceled. If so, the application may takeactions to cause forwarding termination procedures to be implemented orcanceled. These actions could be performed entirely by the applicationand the user's telephony device, or in concert with elements of theforwarding connection unit 300.

FIG. 6 illustrates steps of a method that results in call forwardingprocedures being implemented. The method starts in step S602 when thetriggering unit 304 of the forwarding connection unit 300 obtainsinformation about the location of the subscriber mobile telephony device112. This could be accomplished by having the triggering unit 304interrogate the subscriber mobile telephony device 112, or some otherelement or computer system, to obtain location information that isindicative of the location of the subscriber mobile telephony device112. Alternatively, an application running on the subscriber mobiletelephony device 112 may periodically report the position of thesubscriber mobile telephony device to the triggering unit 304.

In other instances the location of the subscriber mobile telephonydevice 112 may be determined in some other fashion. For example, theposition of the subscriber mobile telephony device could be triangulatedby elements of a mobile telephony service provider, and this informationcould be reported to the triggering unit 304, or the triggering unitcould request the location information from the mobile telephony serviceprovider.

In some embodiments, the IP address through which a subscriber mobiletelephony device 112 registers with the forwarding connection unit 300could be used to determine the location of the subscriber mobiletelephony device 112. The IP address could be the IP address of awireless access point that the subscriber mobile telephony device 112has used to gain access to the data network. The subscriber mobiletelephony device 112 would be presumed to be immediately adjacent to thewireless access point. Thus, if the location of the wireless accesspoint with the IP address is known, the approximate location of thesubscriber mobile telephony device 112 would also be known.

In step S604, the triggering unit 304 compares the location of thesubscriber mobile telephony device 112 to the known native service areaof the subscriber mobile telephony device 112 to determine if thesubscriber mobile telephony device 112 has roamed out of its nativeservice area. If the subscriber mobile telephony device 112 is roaming,then in step S606, the triggering unit 304 causes the implementation offorwarding termination procedures. Specifically, forwarding instructionsare issued to mobile telephony service provider A 114 to have callsdirected to the native telephone number of the subscriber mobiletelephony device 112 forwarded to a forwarding access number (or otherforwarding identifier), as described above. A similar process would beused to cancel call forwarding instructions when the triggering unit 304determines that the subscriber mobile telephony device has returned toits native service area.

In alternate embodiments, the triggering unit 304 of the forwardingconnection unit 300 may monitor the movements of the subscriber mobiletelephony device 112 over an extended period of time. If an analysis ofthe movements of the subscriber mobile telephony device 112 indicatethat the device travels outside its native service area according to aregular pattern, such as every Monday morning, and/or that the devicetravels back into its native service area according to a regularpattern, such as every Friday evening, then this pattern information maybe used to trigger the implementation and cancellation of forwardingtermination procedures. Rather than waiting for the actual location ofthe subscriber mobile telephony device to be obtained or reported,forwarding termination procedures may be automatically implemented andcanceled based on the predicted movements of the device.

In other embodiments, the triggering unit 304 may obtain informationabout travel plans for a user of a telephony device, and thisinformation could be used to automatically implement and/or cancelforwarding termination procedures. For example, the triggering unit 304may obtain information about a user's flights to and back from a countrythat is located outside of the native service area of the subscribermobile telephony device 112. Such information could be obtained from anairline, from a purchasing service that facilitated the purchase of theairline tickets, or from other similar sources. The triggering unit 304could then automatically cause implementation of forwarding terminationprocedures at the point in time when the user should be leaving thenative service area. Likewise, forwarding termination procedures couldbe automatically canceled when the user is supposed to return to alocation within the native service area of the subscriber mobiletelephony device 112.

In a similar fashion, the triggering unit 304 may be able to obtaininformation about actual movements of the user of the telephony device.For example, an airline could report that a particular user has boardeda flight to a foreign country, or that the user has disembarked in thatforeign country. This information could be used by the triggering unitto determine when to cause the implementation of forwarding terminationprocedures. Likewise, information about actual movement of the user backinto the native service area could be used by the triggering unit 304 todetermine when to cancel forwarding termination procedures.

Although the above examples discussed the triggering unit 304 of aforwarding connection unit using travel plans and actual reportedmovements of a user to determine when to implement and cancel forwardingtermination procedures, the same information could be obtained and usedby an application running on a subscriber mobile telephony device forthe same purposes.

In still other embodiments, the triggering unit 304 may obtaininformation from a telephony device to determine if the telephony deviceis outside its native service area. This could include obtaininglocation information from a GPS unit of the telephony device. This couldalso include simply determining the time zone presently set for thetelephony device, which may provide an indication of the location of thetelephony device. Many telephony devices automatically adjust to a newtime zone setting when they move from one time zone to another. Thus,learning the current time zone setting may provide the informationneeded to determine if the telephony device has left its native servicearea, or returned to a location within its native service area.

Some telephony devices have an “airplane mode.” Typically, this meansthat the telephony device no longer attempts to establish a radioconnection to a base station of a cellular telephony system. If thetriggering unit 304 determines that a user has activated an “airplanemode” on his telephony device, this may indicate that the user is flyingaway from his native service area. Thus, learning that the user hasactivated an airplane mode could be the triggering event which causesthe implementation of forwarding termination procedures. Likewise, if atelephony device has been outside its native service area for a periodof time, when the telephone device is set into airplane mode, it mayprovide an indication that the telephony device is returning to itsnative service area, which could trigger the cancelation of forwardingtermination procedures.

In the methods discussed above, the forwarding instruction unit 306 actsto automatically implement and cancel forwarding termination proceduresbased on the occurrence of an event, or based on a prediction. Likewise,an application running on the subscriber mobile telephony device 112 mayitself automatically cause the implementation and cancellation offorwarding termination procedures if the application detects that thedevice has moved out of or back into the subscriber's native callingarea. The application may also automatically cause the implementationand cancellation of forwarding termination procedures when theapplication detects that the subscriber mobile telephony device 112 doesnot have a cellular connection to its native mobile telephony serviceprovider A 114. Similarly, the application may automatically cause theimplementation and cancellation of call forwarding instructions when theapplication detects that a data network connection is available.

The relative quality of a connection between the subscriber mobiletelephony device 112 and a cellular service provider could also be usedto trigger the implementation or cancelation of forwarding terminationprocedures. The quality of the connection can include both signalstrength, as well as other measures of the quality of a connection,which can be affected by interference and other problems. If the qualityof a connection between a subscriber mobile telephony device 112 and acellular service provider falls below a threshold value, this maytrigger the implementation of forwarding termination procedures,assuming a data network connection is also available. Likewise, as thequality of the connection increases above the threshold value, thiscould trigger the cancellation of forwarding termination procedures.

Similarly, the quality of a connection between the subscriber mobiletelephony device 112 and an IP telephony system 124, via a data network,could also trigger the implementation and cancelation of forwardingtermination procedures. The quality of the connection could take intoaccount various measures of data communications, such as latency, packetloss, jitter and other factors. The quality of the connection could alsoinclude a measure of the signal strength between the telephony deviceand a wireless access point.

In some embodiments, anytime that the quality of the connection betweenthe telephony device and an IP telephony system is above a thresholdvalue, forwarding termination procedures are implemented. If the qualityfalls below the threshold value, this triggers the cancelation offorwarding termination procedures.

In some embodiments, both the quality of the connection between asubscriber mobile telephony device 112 and a mobile telephony serviceprovider, as well as the quality of a connection between the subscribermobile telephony device 112 and an IP telephony system 124 could betaken into account when determining whether roaming terminationprocedures should be implemented. For example, roaming terminationprocedures may only be implemented if the quality of a connectionbetween the telephony device and an IP telephony system is above a firstthreshold value, and a quality of a connection between the telephonydevice and a mobile telephony service provider is below a secondthreshold value. Similarly, the quality of both types of connectionscould be used to determine whether to cancel forwarding terminationprocedures.

In some embodiments, the quality of the connections may be measured byan application on the subscriber mobile telephony device. In otherembodiments, the quality of the connection to the IP telephony system124 could be measured by the forwarding connection unit 300 or otherelements of the IP telephony system 124. Likewise, the quality of aconnection between the telephony device and a mobile telephony serviceprovider might be measured by elements of the mobile telephony serviceprovider, and this information could be made available to the telephonydevice or to the IP telephony system 124.

Also, the user might take direct action to cause the implementation andcancellation of forwarding termination procedures. For example, anapplication running on the subscriber mobile telephony device 112 mayprovide a user with the ability to manually cause the implementation andcancellation of forwarding termination procedures.

When an application running on the subscriber mobile telephony device112 is causing the implementation of forwarding termination procedures,the application may be directly communicating with the mobile telephonyservice provider, or the application may communicate with the forwardingconnection unit 300 to request that it cause the implementation orcancellation of forwarding termination procedures. If the application isdirectly interacting with the mobile telephony service provider, theapplication may contact the forwarding connection unit 300 via a datanetwork connection to obtain a forwarding access number. Suchcommunications would also inform the forwarding connection unit 300 thatcalls received on the forwarding access number should be terminated tothe subscriber mobile telephony device 112. Examples of such embodimentsare discussed in more detail below.

In other embodiments, other triggering events may cause theimplementation and cancellation of forwarding termination procedures.For example, if the triggering unit 304 of the forwarding instructionunit 300 determines that the cost of terminating telephonycommunications to a subscriber mobile telephony device 112 via a nativeand/or non-native mobile telephony service provider has risen above athreshold value, the triggering unit 304 could automatically cause theimplementation of forwarding termination procedures. This could occurbecause the subscriber mobile telephony device 112 has traveled outsideits native service area, or for other reasons. Likewise, if thetriggering unit 304 of the forwarding instruction unit 300 determinesthat the cost of terminating telephony communications to a subscribermobile telephony device 112 via a native and/or non-native mobiletelephony service provider has fallen below a threshold value, thetriggering unit 304 could automatically cause the cancelation offorwarding termination procedures.

In another embodiment of the invention, all incoming telephonycommunications are forwarded to the IP telephony system 124 at alltimes. This would require that a dedicated forwarding access number (orother forwarding identifier) be assigned to the subscriber mobiletelephony device 112, and call forwarding instructions would always beactive. Each time that a call is received on the forwarding accessnumber, the forwarding connection unit 300 checks the connection statusof the subscriber mobile telephony device 112 to determine what type ofaccess the subscriber mobile telephony device 112 has. The call is thenterminated to the subscriber mobile telephony device 112 in the mostappropriate manner. This could mean sending the call through a cellularservice provider in a normal manner, or setting up a VOIP telephone linkvia a data network. If more than one connection method is possible,preference rules would determine how the call is connected. For example,the quality of the respective connections to the subscriber mobiletelephony device could determine how the call is connected.

If there is no such access, the incoming telephony communication couldbe sent to voicemail, or to some type of interactive voice responsesystem. Alternatively, the incoming telephony communication could beforwarded to another subscriber device or telephone number.

FIG. 7 illustrates steps of a control method embodying the inventionwhich terminates incoming telephony communications to a subscribermobile telephony device 112 via the most appropriate path. This methodwould be executed by the forwarding connection unit 300 of an IPtelephony system 124 after call forwarding instructions have beenimplemented. For purposes of the following explanation, the subscribermobile telephony device 112 is located in country 2 (see FIG. 1), andthe subscriber mobile telephony device is capable of receiving incomingtelephony communications from mobile telephony service provider B 140.

The method begins in step S702 when an incoming telephony communicationis received on a forwarding access number that has been assigned for thesubscriber mobile telephony device 112. In step S704, the calltermination unit 308 of the forwarding connection unit 300 checks todetermine if the subscriber mobile telephony device 112 is registeredand reachable via a data network connection. If the subscriber mobiletelephony device 112 is registered, in step S706 the call terminationunit 308 checks to determine the quality of the data connection. If thedata connection is capable of supporting a VOIP call to the subscribermobile telephony device 112, then in step S708 a VOIP call isestablished between the IP telephony system 124 and the subscribermobile telephony device 112 over the data network. The receivedtelephony communication is then terminated to the subscriber mobiletelephony device 112 through the VOIP call.

If the quality of the data network connection to the subscriber mobiletelephony device 112 is not sufficient, then in step S710 a check ismade to determine if the user has authorized calls to be terminated tothe subscriber mobile telephony device 112 through non-native mobiletelephony service provider B 140. This will likely result in roamingcharges. However, the user may choose to accept the roaming charges ifthere is no other way of receiving an incoming telephony communication.In this scenario, the forwarding connection unit 300 first checks to seeif it is possible to terminate the call through alternate means. But ifno other means are available, the call is ultimately terminated throughthe non-native mobile telephony service provider B 140, after callforwarding has been canceled.

The result of the decision reached in step S710 could be conditioned onvarious things. For instance, the user may have instructed that allcalls be terminated through non-native mobile telephony service providerB 140 if no other method of terminating the call exists. In otherinstances, the user might specify that calls should only be terminatedthrough a non-native telephony service provider if the call will costless than a threshold amount to complete. In still other instances, theuser might specify that only calls originating from a particular set oftelephone numbers should be completed through a non-native mobiletelephony service provider. This would allow the user to specify thatcertain important people be put through, but that other calls are not.

If the decision in step S710 is that the call should not be terminatedthrough a non-native mobile telephony service provider, then in stepS718 the call is terminated in some other fashion. As discussed above,this could include sending the call to voicemail, playing a recording tothe caller that the called party is unavailable, forwarding the call toan alternate telephone number, or terminating the call in some otherfashion.

If the decision in step S710 is to terminate the call to the subscribermobile telephony device 112 through non-native mobile telephony serviceprovider B 140, in step S712 the forwarding instruction unit 306contacts mobile telephony service provider A 114 and cancels the callforwarding instructions. The call termination unit 308 then sends thecall to the regular native telephone number of the subscriber mobiletelephony device 112 in step S714. This will cause mobile telephonyservice provider A 114 to send the call on to mobile telephony serviceprovider B 140, which ultimately completes the call to the subscribermobile telephony device 112.

Because the call is being routed through the IP telephony system 124,the forwarding connection unit 300 is able to monitor the status of thecall. Once the call is completed, the method proceeds to step S716,where the call forwarding instructions are re-implemented. This ensuresthat further calls directed to the subscriber mobile telephony device112 will be forwarded to the IP telephony system 124.

If the check made in step S704 indicated that the subscriber mobiletelephony device 112 is not registered with the forwarding connectionunit 300, then in step S720 a check is made to determine if it isacceptable to terminate the communication through the non-native mobiletelephony service provider B 140. If the system determines that the callshould not be terminated through non-native mobile telephony serviceprovider B 140, then in step S728 the call would be terminated in someother fashion.

If the decision in step S720 is to terminate the call to the subscribermobile telephony device 112 through a non-native mobile telephonyservice provider, then in step S722 the forwarding instruction unit 306contacts mobile telephony service provider A 114 and cancels the callforwarding instructions. The call termination unit 308 then sends thecall to the regular native telephone number of the subscriber mobiletelephony device 112 in step S724. This will cause mobile telephonyservice provider A 114 to send the call on to mobile telephony serviceprovider B 140, which ultimately completes the call to the subscribermobile telephony device 112. Once the call is completed, the methodproceeds to step S726, where the call forwarding instructions arere-implemented.

FIG. 8 illustrates steps of another method embodying the invention. Thismethod results in a telephony communication being terminated to asubscriber mobile telephony device 112 that is roaming. The call iscompleted through the non-native mobile telephony service provider B140. However, the call is completed in a fashion that will not result inroaming charges.

When a mobile telephony device is located outside of its native callingarea, the device will communicate with a non-native mobile telephonyservice provider. During an initial communication process, thenon-native mobile telephony service provider will recognize that themobile telephony device is a non-native device. As a result, thenon-native mobile telephony service provider will assign a temporarylocal access telephone number to the device. The temporary number isoften known as a mobile subscriber roaming number (MSRN). The non-nativemobile telephony service provider then communicates with the user'snative mobile telephony service provider and informs the native mobiletelephony service provider of the assigned local access telephonenumber. This can be accomplished using a MAP Update Location Message.

The native mobile telephony service provider stores the temporary localaccess telephone number in a home location register that it maintains.The native mobile telephony service provider can obtain the temporarylocal access telephone number using a MAP Provide Roaming Numbermessage. Whenever a call comes in for the subscriber's mobile telephonydevice, the native mobile telephony service provider forwards the callto the temporary local access telephone number. This will route the callto the non-native mobile telephony service provider, which thencompletes the call to the subscriber's mobile telephony device.

Because the local access number assigned to the subscriber mobiletelephony device 112 by the non-native mobile telephony service providerB 140 is stored in the home location register of the native mobiletelephony service provider A 114, this information may be available tothe IP telephony system 124. For purposes of the following explanation,the subscriber mobile telephony device 112 is roaming in country 2, andmobile telephony service provider B 140 has assigned a local accessnumber to the subscriber mobile telephony device 112. The forwardingconnection unit 300 has obtained the local access number from the nativemobile telephony service provider 114. Finally, forwarding instructionsfor the subscriber mobile telephony device have been implemented.

The method begins in step S802, when an incoming telephony communicationdirected to the subscriber mobile telephony device 112 is received bythe IP telephony system 124. In step S804 a check is performed todetermine if the subscriber mobile telephony device 112 is registeredwith the forwarding connection unit 300 and available over a dataconnection. If so, then in step S806 the call is completed to thesubscriber mobile telephony device 112 over the data connection.

If the subscriber mobile telephony device is not available over a dataconnection, the method proceeds to step S810, where a check is performedto determine if the forwarding connection unit 300 has the local accessnumber assigned by the non-native mobile telephony service provider B140. If the local access number is available, in step S812 theforwarding connection unit 300 routes the call over a data network to agateway located in country 2. The gateway in country 2 then contacts andhands the call off to the non-native mobile telephony service provider B140. The non-native mobile telephony service provider B 140 thencompletes the call to the subscriber mobile telephony device 112.

The IP telephony system 124 already has multiple agreements in placewith mobile telephony service providers in multiple countries. Thoseagreements allow the IP telephony system 124 to route calls over a datanetwork to gateways located in various countries. Those gateways canthen hand calls off to the mobile telephony service providers in thosecountries.

By routing the call over the data network until the call arrives in thedesired country, and by having the non-native mobile telephony serviceprovider then complete the call from a local gateway to the subscribermobile telephony device 112, the call can be completed for aconsiderably lower cost than if the call was handled in a traditionalmanner, and roaming charges were incurred. The user would likely have topay a small charge to terminate the call in this fashion. But the chargewould be less than the cost of the roaming charges.

Returning now to FIG. 8, if the local access number is not available, instep S814 a check is made to determine if it is acceptable to terminatethe communication in the traditional manner through the non-nativemobile telephony service provider B 140. If the system determines thatthe call should not be terminated through the non-native mobiletelephony service provider B 140, then in step S822 the call would beterminated in some other fashion.

If the decision in step S814 is to terminate the call to the subscribermobile telephony device 112 in the traditional manner through thenon-native mobile telephony service provider B 140, then in step S816the forwarding instruction unit 306 contacts mobile telephony serviceprovider A 114 and cancels the call forwarding instructions. The calltermination unit 308 then sends the call to the regular native telephonenumber of the subscriber mobile telephony device 112 in step S818. Thiswill cause mobile telephony service provider A 114 to send the call onto mobile telephony service provider B 140, which ultimately completesthe call to the subscriber mobile telephony device 112. Once the call iscompleted, the method proceeds to step S820, where the call forwardinginstructions are re-implemented.

As an additional feature of the call termination processes presentedabove, an enhanced security option is made available. That is, once acommunication request is passed to the IP telephony system 124, callsignaling and media connections between the IP telephony system 124 andthe subscriber mobile telephony device 112 may be encrypted to provide asecure communication session. The encryption techniques that are usedcould be RSA encryption, as described in PKCS#1 v2.1: RSA CryptographyStandard, RSA Laboratories, dated Jun. 14, 2002, or AES encryption asdescribed in Advanced Encryption Standard (AES), Federal InformationProcessing Standards Publication 197, dated Nov. 26, 2001, or thetechniques described in Secure Socket Layer (now Transport LayerSecurity) Protocol, Version 1.2 as described in IETF RFC 5246, datedAugust 2008, all of which are incorporated herein by reference.

In the methods described above, a call forwarding number or some otherform of forwarding identifier is assigned by the forwarding connectionunit 300 when forwarding termination procedures are being implemented.This would likely result in different forwarding access telephonenumbers being used for the same device at different times. However, inother embodiments, the forwarding access telephone number could be adedicated telephone number that is used only for a particular mobiletelephony device.

In the systems and methods described above, a forwarding instructionunit 306 of a forwarding connection unit 300 assigns a forwarding accesstelephone number and issues call forwarding instructions to mobiletelephony service provider A 114. This causes mobile telephone serviceprovider A 114 to forward all calls made to the native telephone numberof the subscriber mobile telephony device 112 to the assigned forwardingaccess number.

In some cases, it may be impossible for the forwarding instruction unit306 of a forwarding connection unit 300 to interact directly with amobile telephony service provider to cause the mobile telephony serviceprovider to implement and/or cancel call forwarding instructions. Inthose cases, however, it may be possible for call forwardinginstructions to be implemented and canceled by issuing such instructionsto the mobile telephony service provider from a subscriber's mobiletelephony device. As will be explained below, in some embodiments, asoftware application running on a subscriber's mobile telephony devicecan cause call forwarding instructions to be issued from thesubscriber's mobile telephony device. In other embodiments, thesubscriber may need to take some type of positive action to causeappropriate call forwarding instructions to be issued from thesubscriber's mobile telephony device.

Instructions to implement and cancel call forwarding can be issued to amobile telephony service provider from a subscriber's mobile telephonydevice by dialing predetermined patterns of characters and/or numbers.The call forwarding activation and deactivation codes can vary from onemobile telephony service provider to the next. Thus, it is important toknow which mobile telephony service provider is providing the nativeservice to a subscriber's mobile telephony device to thereby know whichstring of characters must be dialed implement or cancel call forwardinginstructions.

Also, many mobile telephony service providers allow for different typesof call forwarding instructions. Some call forwarding instructions canbe unconditional, whereas other call forwarding instructions can beconditional based on various factors. For example, in many mobiletelephony systems a first call forwarding activation code causes allcalls placed to the native telephone number of a subscriber's mobiletelephony device to be forwarded to a specified forwarding telephonenumber. A second call forwarding activation code causes a call placed tothe native telephone number of a subscriber's mobile telephony device tobe forwarded to a specified forwarding telephone number only if thesubscriber's mobile telephony device is already busy with another call.A third call forwarding activation code causes calls to the nativetelephone number of a subscriber's mobile telephony device to beforwarded to a forwarding telephone number only if the call is notanswered by the subscriber's mobile telephony device within a certainperiod of time after ringing begins.

As with the call forwarding activation codes, different deactivationcodes may be required to deactivate each of these different types ofcall forwarding instructions. The deactivation codes may also vary fromone mobile telephony service provider to the next.

Most subscribers are not aware of the codes that must be dialed on theirmobile telephony device to activate and deactivate call forwarding.Also, in many systems and methods embodying the invention, the callforwarding number that is assigned by the forwarding connection unit 300will not be known until it is actually issued by the forwardingconnection unit 300. And that may not occur until the subscriber'smobile telephony device registers with the forwarding connection unit300 via a data connection.

For these reasons, if it is necessary for a subscriber to issue callforwarding instructions to the mobile telephony service provider bydialing a particular string of characters on the subscriber's mobiletelephony device, it is helpful for the forwarding connection unit 300to provide the subscriber, or an application on the subscriber's mobiletelephony device, with the string of characters that must be dialed.Several different ways of accomplishing this task are explained below.

In many mobile telephony systems, a subscriber can cause unconditionalcall forwarding to be implemented by dialing the string “*21*[forwardingtelephone number]#”. The forwarding telephone number is the telephonenumber to which calls will be forwarded. In the United States, theforwarding telephone number typically includes 10 digits, including thearea code and the assigned telephone number. Once unconditional callforwarding instructions have been implemented, they can be canceled bydialing the string “##21#”.

In many of those same mobile telephony systems, several different typesof conditional call forwarding can be implemented by dialing differentstrings of characters. For example, some telephony systems can beinstructed to forward a call to a forwarding telephone number if thesubscriber's mobile telephony device is busy with another call bydialing the character string “*67*[forwarding telephone number]#”. Thistype of conditional call forwarding can be canceled by dialing thecharacter string “##67#”. Other types of conditional call forwarding canbe implemented and canceled by dialing other character strings.

In the context of this invention, the point of issuing call forwardinginstructions is to cause a subscriber's native mobile telephony serviceprovider to forward an incoming call directed to the native telephonenumber of the subscriber's mobile telephony device to be forwarded to aforwarding access number that has been assigned by a forwardingconnection unit 300 of an IP telephony system 124. Once the incomingcall is re-directed to the forwarding access number, the IP telephonysystem 124 completes the call to the subscriber's mobile telephonydevice over a data connection. This requires that the subscriber'smobile telephony device already be registered with the forwardingconnection unit 300 via a data connection.

If the forwarding instruction unit 306 of a forwarding connection unit300 is unable to interact directly with the subscriber's native mobiletelephony service provider to cause the implementation and cancellationof call forwarding instructions, then it would be advantageous for suchcall forwarding instructions to be issued by dialing the appropriatecharacter string from the subscriber's mobile telephony device.Typically, the call forwarding instructions would be issued from thesubscriber's mobile telephony device shortly after the subscriber'smobile telephony device registers with a registration unit 302 of theforwarding connection unit 300. If a forwarding access telephone numberis selected upon registration, this is the earliest point in time atwhich the forwarding access telephone number will be known.

In the following example, the forwarding connection unit 300 providesthe subscriber, or an application on the subscriber's mobile telephonydevice, with a character string that must be dialed from thesubscriber's mobile telephony device to implement appropriate callforwarding instructions. In some instances, the subscriber then causesthat character string to be dialed to implement the call forwardinginstruction. In other instances, an application on the subscriber'smobile telephony device causes the character string to be dialed toimplement the call forwarding instructions.

FIG. 9 illustrates steps of a method that would be performed when asubscriber's mobile telephony device registers with a forwardingconnection unit 300 to implement forwarding procedures by dialing acharacter string from the subscriber's mobile telephony device. Asexplained above, in some embodiments, the subscriber's mobile telephonydevice automatically contacts the forwarding connection unit 300whenever it is able to establish a data connection, regardless of howthat connection is established. In other instances, the subscriber takesdirect action to cause his mobile telephony device to register with theforwarding connection unit 300. In still other instances, the forwardingconnection unit may initiate contact to the subscriber's mobiletelephony device to cause registration to occur.

The method begins in step S902, where the forwarding instruction unit306 assigns a forwarding access telephone number for the subscriber'smobile telephony device. As explained above, the forwarding accesstelephone number is stored in a registration database maintained by theIP telephony system 124 against the native telephone number and the IMSInumber of the subscriber's mobile telephony device.

Once the forwarding access number is assigned, in step S904 theforwarding instruction unit 306 determines the string of characterswhich must be dialed from the subscriber's mobile telephony device toinstruct the subscriber's native mobile telephony service provider toimplement the desired type of call forwarding.

As explained above, different codes are used by different mobiletelephony service providers to implement and cancel the same type ofcall forwarding instructions. Thus, the forwarding instruction unit 306needs to know what mobile telephony service provider is providing thenative mobile telephony service to the subscriber's telephony device sothat the correct character string can be determined. In someembodiments, a call forwarding code database 310 containing the codes orcharacter strings that are used by various different mobile telephonyservice providers to implement and cancel various different types ofcall forwarding is part of the forwarding connection unit 300, or partof the IP telephony system 124. The call forwarding instruction unitwould consult this database to obtain information about how to determinethe correct character string.

As also explained above, many mobile telephony service providers arecapable of implementing multiple different types of call forwarding,each of which is implemented and canceled by different characterstrings. Thus, the forwarding instruction unit 306 also needs todetermine what type of call forwarding the subscriber wishes toimplement, and then determine the character string to use to implementthe desired type of call forwarding within the subscriber's mobiletelephony service provider system.

In some embodiments, the subscriber's preferences about the type of callforwarding will already have been provided to the forwarding connectionunit 300 during a registration process. In other instances, thesubscriber may be queried about the type of call forwarding he wouldlike to implement each time that the subscriber's mobile telephonydevice registers with the forwarding connection unit 300. In someembodiments, if the subscriber has not made a selection regarding thetype of call forwarding instructions he wishes to implement, theforwarding connection unit 300 selects a default type of callforwarding, such as unconditional call forwarding.

Once the forwarding instruction unit 306 has determined the characterstring that must be dialed to implement the desired type of callforwarding to the assigned forwarding access number, in step S906, theforwarding instruction unit 306 provides the determined character stringto the subscriber and/or to the subscriber's mobile telephony device inany one of multiple different ways. In some embodiments, the forwardinginstruction unit 306 causes a message to be displayed on thesubscriber's mobile telephony device. The message includes thedetermined character string. The message may also include instructionsfor dialing the determined character string.

In some embodiments, the message could be sent to a software applicationthat is running on the subscriber's mobile telephony device, or that ispresent on a memory card or SIM card of the device, and which is incommunication with the forwarding instruction unit 306 via a dataconnection. The software application then causes the message to bedisplayed on the subscriber's mobile telephony device. In otherembodiments, the forwarding instruction unit 306 could cause a SMS orMMS message to be sent to the subscriber's mobile telephony device via atelephony system connection. In still other embodiments, a pushnotification service could be used to send the desired message to theuser's mobile telephony device.

In the example given above, the character string “*21*[forwardingtelephone number]#” is used to implement unconditional call forwardingto the forwarding telephone number. If the forwarding access numberassigned by the forwarding instruction unit 306 is 703.555.1234, themessage sent to the subscriber's mobile telephony device would includethe string “*21*7035551234#”. The subscriber would dial that characterstring from his mobile telephony device to implement call forwarding tothe telephone number 703.555.1234.

In some instances, it may be relatively easy for the subscriber to copythe provided character string, and to then insert that copied characterstring into the native telephone dialer of the subscriber's mobiletelephony device. In other instances, the subscriber's mobile telephonydevice may have functionality that allows the subscriber to highlight orselect the character string in the displayed message, and to then causethe mobile telephony device to dial the highlighted/selected characterstring. In such instances, it will be relatively easy for the subscriberto cause his mobile telephony device to dial provided character stringto cause the implementation of call forwarding instructions.

One type of call forwarding activation code causes calls to the nativetelephone number of a subscriber's mobile telephony device to beforwarded to a forwarding telephone number if the call is declined bythe subscriber (e.g., by pressing decline when the call is firstreceived by the mobile telephony device and the mobile telephony devicebegins ringing). This fourth type of call forwarding activation code maybe advantageous in allowing the subscriber to choose how an incomingcall is ultimately connected to his mobile telephony device.

For example, in some instances, a subscriber may find that heexperiences superior call quality using a cellular telephony channel, asopposed to a data channel. Thus, depending upon the nature of the phonecall, the user may prefer that an incoming call be connected to hismobile telephony device via a cellular telephony channel, which wouldincur roaming charges, as opposed to receiving the call through a datanetwork via an assigned call forwarding number.

If conditional call forwarding instructions are issued to thesubscriber's native mobile telephony service provider that only resultin a call being forwarded to a forwarding access number if thesubscriber declines an incoming call, the subscriber will be able tochoose how the call is connected to his mobile telephony device. If thesubscriber simply answers an incoming telephone call when his mobiletelephony device begins to ring, the call will be connected to thesubscriber's mobile telephony device via a roaming cellular connection,which might provide higher call quality. On the other hand, if thesubscriber declines the call, the subscriber's native mobile telephonyservice provider will forward the call to a forwarding access numberassigned by the forwarding connection unit 300, and the call will berouted to the subscriber's mobile telephony device via a dataconnection, as described above.

FIG. 10 illustrates a method in which the forwarding instruction unit306 sends a character string that is to be used to implement callforwarding to a subscriber's mobile telephony device in a way that makesit easy for the subscriber to dial the provided string. In step S1002,the forwarding instruction unit 306 assigns a forwarding accesstelephone number. Once the forwarding access telephone number isassigned, the forwarding instruction unit 306 determines the characterstring that must be dialed from the subscriber's mobile telephony deviceto implement a desired type of call forwarding to the assignedforwarding access number in step S1004. In step S1006, the forwardinginstruction unit 306 provides the character string to the subscriber'smobile telephony device in a manner that allows the character string tobe recorded as part of a contact in a contact list that is present onthe subscriber's mobile telephony device.

In some embodiments, the forwarding instruction unit 306 causes atelephone call or a SMS/MMS message to be sent to the subscriber'smobile telephony device. The call or SMS/MMS message includes user IDinformation. The user ID information includes the determined characterstring as the “telephone number” of the calling party. The name providedin the caller ID information could provide an indication of the functionof the character string. For example, the name in the caller IDinformation could read “Implement Call Forwarding for Mobile Roaming.”

When the call or message is received by the subscriber's mobiletelephony device, the caller ID information that includes the determinedcharacter string, and possibly a label indicating the purpose of thecharacter string, will be recorded in the incoming call log of thesubscriber's mobile telephony device. Many mobile telephony devicesprovide the subscriber with the ability to use the caller ID informationthat has been captured for an incoming telephony communication topopulate a new contact entry in a contact list that is stored on thesubscriber's mobile telephony device. Thus, the subscriber is able tostore a new contact in his contact list that includes the characterstring that must be dialed to implement call forwarding as the“telephone number” of the new contact. Likewise, the name in the callerID information, which can include a label indicating the purpose of thecharacter string, will appear as the name of the new contact.

Once the new contact has been stored on the subscriber's mobiletelephony device, the subscriber can request that a call be placed tothat contact. This would cause the subscriber's mobile telephony deviceto dial the character string which implements the required type of callforwarding.

The forwarding instruction unit 306 could also place multiple calls orsend multiple messages to the subscriber's mobile telephony device todeliver character strings and corresponding labels for multipledifferent types of call forwarding instructions. For example, theforwarding instruction unit 306 could place a first call to thesubscriber's mobile telephony device with a character string used toimplement unconditional call forwarding to an assigned forwarding accessnumber. The subscriber would cause this first character string to bestored as part of a first new contact under the name “ImplementUnconditional Call Forwarding.” The forwarding instruction unit 306could then place a second call to the subscriber's mobile telephonydevice with the character string used to implement a type of conditionalcall forwarding to the assigned forwarding access number which occursonly if the subscriber's mobile telephony device is busy, or if thesubscriber declines an incoming call. The subscriber would cause thissecond character string to be stored as part of a second new contactunder the name “Implement Conditional Call Forwarding.” The subscribercould then choose which type of call forwarding is to be implemented byplacing a call to the contact which causes the desired type of callforwarding instructions to be implemented.

In the same way that a character string can be stored as a contact thatis used to implement a desired form of call forwarding, a contact with acharacter string that is dialed to cancel call forwarding could also bestored on the subscriber's mobile telephony device under a name such as“Cancel Call Forwarding.” As noted above, in some mobile telephonyservice provider systems, the character string “##21#” can be dialedfrom a mobile telephony device to cancel unconditional call forwarding.Thus, the forwarding instruction unit 306 could send a call or a messageto the subscriber's mobile telephony device that includes caller IDinformation including the character string “##21#” as the sourcetelephone number, and “Cancel Unconditional Call Forwarding” as thename. The subscriber could then create a new contact with thisinformation. And once created, the subscriber could simply request thata call be placed to the contact with the name “Cancel Unconditional CallForwarding” to cause his mobile telephony device to dial the characterstring which causes the cancellation of unconditional call forwarding.

Because the character string used to cancel call forwarding instructionsdoes not typically include a telephone number, it would be possible fora subscriber to store contacts having the character strings forcancellation of each type of call forwarding instructions. Thosecontacts could then be re-used multiple times whenever a subscriberwishes to cancel a particular type of call forwarding.

On the other hand, if a new call forwarding access number is assigned toa subscriber's mobile telephony device each time the mobile telephonydevice registers with the forwarding connection unit 300, it would benecessary for the subscriber to store a new contact in his contact list(with a character string that includes the newly assigned forwardingaccess telephone number) each time that the mobile telephony devicere-registers with the forwarding connection unit 300. It is unlikelythat a previously stored contact could be re-used to implementforwarding operations at a later point in time, because at that laterpoint in time a new forwarding access number will have been assigned tothe subscriber's mobile telephony device. And that new forwarding accesstelephone number will not be reflected in the telephone numberinformation that is present in the first contact that was stored in thesubscriber's contact list.

However, if the forwarding connection unit 300 assigns a staticforwarding access number to the subscriber's mobile telephony device foran enduring period of time, the subscriber could store a contact in hiscontact list having a telephone number that is the character stringincluding the static forwarding access number. That contact could bere-used multiple times by the subscriber to implement call forwardinginstructions. Software on the subscriber's mobile telephony device couldautomatically create the contact.

For example, assume that a subscriber travels to another country onbusiness, that country being outside the subscriber's native telephonyservice area, and the subscriber intends to remain in the country for aweek. Under those circumstances, the forwarding connection unit 300could assign a forwarding access number to the subscriber's mobiletelephony device that will remain tied to the mobile telephony devicefor the entire week. A first contact including the character string forimplementing call forwarding to the assigned forwarding access numbercould then be stored on the subscriber's mobile telephony device. Asecond contact having the character string used to cancel those callforwarding instructions could also be stored on the subscriber's mobiletelephony device. This would allow the subscriber to selectivelyimplement and cancel call forwarding instructions (and thus, forwardingoperations) by requesting that calls be placed to the first and secondstored contacts over the duration of his visit to the foreign country.

In the systems and methods described above in connection with FIGS. 9and 10, it was assumed that the forwarding connection unit 300 wasunable to interact directly with the mobile telephony service providerthat provides telephony service to a subscriber's mobile telephonydevice to selectively implement and cancel call forwarding instructions.For this reason, in the systems and methods discussed above, thecharacter strings required to implement and cancel call forwardinginstructions are provided to the subscriber, via his mobile telephonydevice. The subscriber directly interacts with his device to selectivelyimplement and cancel call forwarding instructions (and thus forwardingoperations).

Unfortunately requiring the subscriber to implement and cancel callforwarding instructions is not ideal. Some subscriber will likely viewthis as inconvenient and/or too difficult. Also, there is a danger thata subscriber may implement call forwarding instructions (to implementforwarding operations), and then forget to cancel the call forwardinginstructions once forwarding operations are longer needed or desired.

In other situations, the subscriber may not be aware when his mobiletelephony device can no longer maintain a data connection with theforwarding connection unit 300. If that occurs, the subscriber may noteven be aware that he should cancel call forwarding instructions so thatincoming calls can be received (albeit in a more expensive fashion) viaa normal cellular connection.

For all these reasons, in some situations it is desirable for theimplementation and cancellation of call forwarding instructions to beperformed automatically at the appropriate times. However, as alsoexplained above, in some situations the only way to implement and cancelcall forwarding instructions is have the subscriber's mobile telephonydevice dial a particular character string.

FIG. 11 illustrates steps of a method where call forwarding instructionscan be automatically implemented and canceled, without requiring theuser to take any active steps, even through a character string must bedialed by the subscriber's mobile telephony device to implement andcancel the call forwarding instructions. In step S1102, the forwardinginstruction unit 306 assigns a forwarding access telephone number. Oncethe forwarding access telephone number is assigned, in step S1104 theforwarding instruction unit 306 determines the character string thatmust be dialed from the subscriber's mobile telephony device toimplement the desired type of call forwarding to the assigned forwardingaccess number.

In step S1106, the forwarding instruction unit 306 causes thesubscriber's mobile telephony device to dial the determined characterstring. In some embodiments, it may be possible for the forwardinginstruction unit 306 to interact directly with the subscriber's mobiletelephony device via a data connection to cause the native dialer of thesubscriber's mobile telephony device to dial the determined characterstring. In other embodiments, the forwarding instruction unit 306 mayprovide the character string to an application that is present on thesubscriber's mobile telephony device, along with a direction to causethe character string to be dialed. The application would then cause thenative dialer on the subscriber's mobile telephony device to dial thecharacter string.

In a similar fashion, the forwarding instruction unit 306 can determinea character string that will cause call forwarding to be canceled, andthe forwarding instruction unit 306 can cause the native dialer on thesubscriber's mobile telephony device to dial the character string thatcancels call forwarding. This could occur because the forwardinginstruction unit 306 is able to interact directly with the native dialervia a data connection, or because the forwarding instruction unit 306instructs an application on the subscriber's mobile telephony device tocause the dialing of the cancellation string.

In alternate embodiments, the forwarding instruction unit 306 maycontact and/or control the native dialer of the user's mobile telephonydevice through a connection via a cellular data channel, as opposed someother type of data connection. The forwarding instruction unit 306 mightalso provide instructions to an application running on the subscriber'smobile telephony device via the cellular data connection.

In still other embodiments, the forwarding instruction unit 306 mayprovide instructions to an application running on the subscriber'smobile telephony device via a push notification. For example, theforwarding instruction unit 306 may cause a push notification to be sentto the subscriber's mobile telephony device that includes the message“Would you like to implement forwarding operations?” If the userresponds affirmatively, a message would be delivered to an applicationon the subscriber's mobile telephony device that causes the applicationto access and control the native dialer on the subscriber's mobiletelephony device so that a character string is dialed to implement callforwarding to an assigned forwarding access number. In some instances,the push notification will also cause the application to load and run.Similar push notifications could be used in a similar fashion to causethe cancellation of call forwarding instructions, and thus thetermination of forwarding operations.

In many of the foregoing descriptions, instructions were provided to asoftware application running on a subscriber mobile telephony device112, or instructions or communications were received from such anapplication. Also, in some of the foregoing examples, a softwareapplication on a subscriber mobile telephony device 112 takes variousactions, such as displaying messages to a user, reporting the currentlocation of the subscriber mobile telephony device 112, causing aforwarding connection unit 300 to implement or cancel call forwardinginstructions, or instructing a native dialer of the subscriber mobiletelephony device to dial character strings used to implement and cancelcall forwarding instructions.

In alternate embodiments of the invention, a browser running on thesubscriber mobile telephony device 112 may access a software applicationthat is running on some other device via a data network connection. Thesoftware application could be running on a remote server that isaccessible via a data network connection. The software applicationrunning elsewhere, and accessible via a browser on the subscriber mobiletelephony device 112 may provide all of the same functionality as anapplication running on the subscriber mobile telephony device itself112. Thus, any references in the foregoing description and the followingclaims to an application running on the subscriber mobile telephonydevice 112 are intended to also encompass embodiments andimplementations where a browser running on the subscriber mobiletelephony device 112 accesses a software application running elsewherevia a data network.

While foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof.

The invention claimed is:
 1. A method, performed by one or more computerprocessors, of performing forwarding termination procedures for atelephony device that has been assigned a native identifier by a mobiletelephony service provider, the method comprising: determining a qualityof a connection that the telephony device has, if any, with the mobiletelephony service provider and a quality of a connection that thetelephony device has, if any, with an Internet protocol (IP) telephonyservice provider; causing forwarding termination procedures to beimplemented when the telephony device has no connection with the mobiletelephony service provider or when a quality of a connection thetelephony device has with the mobile telephony service provider is belowa first threshold value, and when the quality of a connection that thetelephony device has with the IP telephony service provider is above asecond threshold value, wherein causing forwarding terminationprocedures to be implemented comprises: causing the mobile telephonyservice provider to implement call forwarding instructions for thetelephony device such that when the mobile telephony service providerreceives an incoming telephony communication directed to the nativeidentifier assigned to the telephony device, the mobile telephonyservice provider causes the incoming telephony communication to beforwarded to a forwarding identifier associated with the IP telephonyservice provider; receiving a forwarded telephony communication directedto the forwarding identifier that has been forwarded from the mobiletelephony service provider; and connecting the forwarded telephonycommunication to the telephony device via a data network; checking,periodically, after forwarding termination procedures have beenimplemented, to determine a quality of a connection that the telephonydevice has established with the mobile telephony service provider, ifany, and/or determine whether a quality of the connection that thetelephony device has with the IP telephony service provider, if any, isstill above the second threshold value; and causing the forwardingtermination procedures to be canceled when it is determined either thatthe quality of the connection that the telephony device has with themobile telephony service provider is at or above the first thresholdvalue or that the quality of the connection that the telephony devicehas with the IP telephony service provider has fallen below the secondthreshold value, wherein causing forwarding termination procedures to becanceled comprises: causing a query to be sent to a user of thetelephony device, the query asking whether the user wishes forforwarding termination procedures to be canceled; and receiving aresponse to the query, wherein the step of causing the forwardingtermination procedures to be canceled is only performed if the receivedresponse to the query indicates that the user wishes for forwardingtermination procedures to be canceled.
 2. The method of claim 1, whereinthe step of causing forwarding termination procedures to be implementedcomprises automatically causing the implementation of call forwardingprocedures without seeking or obtaining user input.
 3. The method ofclaim 1, wherein causing forwarding termination procedures to beimplemented further comprises: causing a query to be sent to a user ofthe telephony device, the query asking whether the user wishes forforwarding termination procedures to be implemented; and receiving aresponse to the query, wherein the step of causing forwardingtermination procedures to be implemented is only performed if thereceived response to the query indicates that the user wishes forforwarding termination procedures to be implemented.
 4. A system forperforming forwarding termination procedures for a telephony device thathas been assigned a native identifier by a mobile telephony serviceprovider, comprising: means for determining a quality of a connectionthat the telephony device has, if any, with the mobile telephony serviceprovider and a quality of a connection that the telephony device has, ifany, with an Internet protocol (IP) telephony service provider; andmeans for causing forwarding termination procedures to be implementedwhen the telephony device has no connection with the mobile telephonyservice provider or when a quality of the connection the telephonydevice has with the mobile telephony service provider is below a firstthreshold value, and when the quality of the connection that thetelephony device has with the IP telephony service provider is above asecond threshold value, wherein the causing means comprises: means forcausing the mobile telephony service provider to implement callforwarding instructions for the telephony device such that when themobile telephony service provider receives an incoming telephonycommunication directed to the native identifier assigned to thetelephony device, the mobile telephony service provider causes theincoming telephony communication to be forwarded to a forwardingidentifier associated with the IP telephony service provider; means forreceiving a forwarded telephony communication directed to the forwardingidentifier that has been forwarded from the mobile telephony serviceprovider; means for connecting the forwarded telephony communication tothe telephony device via a data network; means for checking,periodically, after forwarding termination procedures have beenimplemented, to determine a quality of a connection that the telephonydevice has established with the mobile telephony service provider, ifany, and/or determine whether a quality of the connection that thetelephony device has with the IP telephony service provider, if any, isstill above the second threshold value; and means for causing theforwarding termination procedures to be canceled when it is determinedeither that the quality of the connection that the telephony device haswith the mobile telephony service provider is at or above the firstthreshold value or that the quality of the connection that the telephonydevice has with the IP telephony service provider has fallen below thesecond threshold value, wherein the means for causing forwardingtermination procedures to be canceled comprises: means for causing aquery to be sent to a user of the telephony device, the query askingwhether the user wishes for forwarding termination procedures to becanceled; and means for receiving a response to the query, wherein themeans for causing the forwarding termination procedures to be canceledcancels the forwarding termination procedures only if the receivedresponse to the query indicates that the user wishes for forwardingtermination procedures to be canceled.
 5. A system for performingforwarding termination procedures for a telephony device that has beenassigned a native identifier by a mobile telephony service provider,comprising: a triggering unit comprising at least one processor thatdetermines a quality of a connection that the telephony device has, ifany, with the mobile telephony service provider, and a quality of aconnection that the telephony device has, if any, with an InternetProtocol (IP) telephony service provider; a forwarding instruction unitcomprising at least one processor that: causes forwarding terminationprocedures to be implemented when the telephony device has no connectionwith the mobile telephony service provider or when a quality of aconnection the telephony device has with the mobile telephony serviceprovider is below a first threshold value, and when the quality of aconnection that the telephony device has with the IP telephony serviceprovider is above a second threshold value, wherein the forwardinginstruction unit causes the mobile telephony service provider toimplement call forwarding instructions for the telephony device suchthat when the mobile telephony service provider receives an incomingtelephony communication directed to the native identifier assigned tothe telephony device, the mobile telephony service provider causes theincoming telephony communication to be forwarded to a forwardingidentifier associated with the IP telephony service provider; whereinafter forwarding termination procedures have been implemented, thetriggering unit periodically checks to determine either whether aquality of a connection that the telephony device has established withthe mobile telephony service provider, if any, has risen above the firstthreshold value, or to determine whether a quality of a connection thatthe telephony device has with the IP telephony service provider, if any,is still above the second threshold value and wherein the forwardinginstruction unit causes the forwarding termination procedures to becanceled when the triggering unit determines either that that thequality of the connection that the telephony device has with the mobiletelephony service provider is above the second threshold value, or thatthe quality of the connection that the telephony device has with the IPtelephony service provider has fallen below the second threshold value,and wherein when the triggering unit determines that forwardingtermination procedures should be cancelled, the forwarding instructionunit causes a query to be sent to a user of the telephony device, thequery asking whether the user wishes for forwarding terminationprocedures to be cancelled, wherein the forwarding instruction unitreceives a response to the query from the user, and wherein theforwarding instruction unit causes the forwarding termination proceduresto be cancelled only when the received response to the query indicatesthat the user wishes for forwarding termination procedures to becancelled; and a call termination unit comprising at least one processorthat receives a forwarded telephony communication directed to theforwarding identifier that has been forwarded from the mobile telephonyservice provider, and that connects the forwarded telephonycommunication to the telephony device via a data network.
 6. The systemof claim 5, wherein the forwarding instruction unit causes forwardingtermination procedures to be automatically implemented without seekingor obtaining user input.
 7. The system of claim 5, wherein when thetriggering unit determines that forwarding termination procedures shouldbe implemented, the forwarding instruction unit causes a query to besent to a user of the telephony device, the query asking whether theuser wishes for forwarding termination procedures to be implemented,wherein the forwarding instruction unit receives a response to the queryfrom the user, and wherein the forwarding instruction unit causes theforwarding termination procedures to be implemented only if the receivedresponse to the query indicates that the user wishes for forwardingtermination procedures to be implemented.